Funds are being requested in this application to upgrade the Imaging Core Facility at U.T. Southwestern Medical Center at Dallas. The Imaging Core Facility was founded in 1988 with seed money from the Texas Permanent University Fund. Its four workstations for digital microscopy, laser confocal microscopy, fluorescence recovery after photobleaching (FRAP) and off-line image processing are extensively used by several laboratories. We are proposing to upgrade the digital microscope workstation by replacing the outdated and difficult to use image processor, by adding equipment for precise temperature control for experiments involving live cells, by adding optics for phase and high resolution DIC microscopy, by expanding the real time, low-light level capabilities with an intensified CCD camera and Super VHS time lapse recorder, and by acquiring the hardware and software to do quantitative optical sectioning and out of focus deconvolution. We propose to upgrade the confocal workstation by adding a Z-axis controller and step focus motor for quantitative optical sectioning, by connecting it to Ethernet and by replacing the existing laser with a Kr-Ar laser. For the FRAP instrument we are requesting a laser beam profiler for easy and accurate measurement of laser beam diameter. For the off-line processing workstation we are requesting a video printer for production of publication quality black and white and color hard copy, and an optical memory disk recorder for high resolution storage and display of images. It is hoped that with these additions the Imaging Core Facility will become a state-of-the-art facility for biomedical research and will better meet the needs of the major users.